The present invention relates to an apparatus for controllably focusing ultrasonic acoustical energy to a desired position within a liquid stream by manipulation of the shape of a wave generator used to propagate acoustic energy as well as by the selection of the shape of a chamber within which the acoustic energy is applied to the liquid. The controlled application of this energy allows one to change the properties of the stream, change the properties of constituents contained within the liquid stream, or both.
The present invention provides an apparatus for controllably focusing ultrasonic acoustical energy within a liquid stream. The apparatus consists of an ultrasonic acoustical wave generator that, when stimulated, emits ultrasonic acoustical energy in the form of vibrations from a tip. The tip is located at a distal end of the generator. The apparatus also has a chamber adapted to pass a liquid from the liquid stream therethrough. At least one acoustically reflective surface is located within the chamber for receiving the acoustical energy transmitted into the liquid stream from the tip of the generator and reflecting that energy to a desired position within the liquid stream to cause a desired effect on the stream.
In another embodiment, the apparatus is adapted to change the properties of the liquid stream itself by controllably focusing ultrasonic acoustical energy within that stream. This apparatus consists of an ultrasonic acoustical wave generator ending in the tip which is submerged in the liquid stream that, when stimulated, emits ultrasonic acoustical energy in the form of vibrations from a tip. A chamber is adapted to receive the liquid from the liquid stream and to enable the liquid to flow therethrough. The chamber has at least one acoustically reflective surface and an opening through which the ultrasonic acoustical energy is directed toward the acoustically reflective surface. The acoustically reflective surface reflects the energy to at least one desired focal point.
In another embodiment, the apparatus is adapted to change the properties of constituents contained within a liquid stream by controllably focusing ultrasonic acoustical energy within that stream. This apparatus has an ultrasonic acoustical wave generator terminating in a tip submerged in the liquid stream that, when stimulated, emits in a desired direction ultrasonic acoustical energy in the form of vibrations. A chamber having acoustically reflective walls is also provided. This chamber has an inlet adapted to receive the liquid from the liquid stream and an outlet adapted to pass the liquid to a position exterior to the chamber. The acoustically reflective walls serve to reflect the energy transmitted from the tip and focus that energy to a desired position within the liquid stream.
As used herein, the term xe2x80x9cliquidxe2x80x9d refers to an amorphous (noncrystalline) form of matter intermediate between gases and solids, in which the molecules are much more highly concentrated than in gases, but much less concentrated than in solids. A liquid may have a single component or may be made of multiple components. The components may be other liquids, solids and/or gases. For example, a characteristic of liquids is their ability to flow as a result of an applied force. Liquids that flow immediately upon application of force and for which the rate of flow is directly proportional to the force applied are generally referred to as Newtonian liquids. Some liquids have abnormal flow response when force is applied and exhibit non-Newtonian flow properties.
As used herein, the term xe2x80x9cnodexe2x80x9d or xe2x80x9cnodal planexe2x80x9d means the point on the mechanical excitation axis of the ultrasonic acoustical wave generator at which no mechanical excitation motion of the wave generator occurs upon excitation by ultrasonic acoustical energy. The node sometimes is referred to in the art, as well as in this specification, as the nodal point or nodal plane.
The term xe2x80x9cclose proximityxe2x80x9d is used herein in a qualitative sense only. That is, the term is used to mean that the ultrasonic acoustical wave generator is sufficiently close to the entrance of the chamber to apply the ultrasonic energy primarily to the reservoir of liquid contained within the chamber. The term is not used in the sense of defining specific distances from the chamber.
As used herein, the term xe2x80x9cconsisting essentially ofxe2x80x9d does not exclude the presence of additional materials which do not significantly affect the desired characteristics of a given composition or product. Exemplary materials of this sort would include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, catalysts, solvents, particulates and materials added to enhance processability of the composition.